Donaldson-Thomas theory is a counting theory of curves on a Calabi-Yau threefold. A curve is an ideal sheaf on the threefold. When the threefold is toric, the virtual count of such curves (the Donaldson-Thomas invariant), can be computed by summing up the contributions of the torus-fixed points in the moduli space of ideal sheaves. Such fixed points have a nice combinatorial interpretation as "configurations of boxes" (partitions). Thus, curve counting is the same as box counting in the toric case.